Method of making nut blanks



y 1934- .1. w. GIBNEY 1,957,952

METHOD OF MAKING NUT BLANK S Filed Dec. 29, 1933 2 ished blanks.

Patented May 8, 1934 UNITED STATES PATENT OFFICE METHOD OF MAKING NUT BLANKS Application December 29, 1933, Serial No. 704,446

7 Claims.

This invention relates to the production of hexagonal nut blanks from bars or strips of cold metal.

The object of the invention is to provide a method by the practice of which nut blanks ready for threading may be made from cold bars or strips of metal, rapidly and with a low percentage of power, minimum distortion of the metal, and very small amount of waste.

In practicing this method a strip of metal,

which is somewhat thinner than, but is of substantially the same width as the blanks to be produced, is cut obliquely so as to form lozenge or rhombic pieces. These pieces are, in a shap- 5 ing mechanism, subjected to pressure exerted in the direction of their longer diagonals, and by such pressure compressed into pieces which are substantially hexagonal in outline and expanded sidewise to practically the thickness of the fin- The pieces are then, in a hexagonal die, subjected to the action of a punch or punches which will recess one or both faces and cause an edgewise expansion of the metal to final hexagonal outline with smooth edge faces.

Finally the blanks are pierced by punching out the small amount of metal remaining at the bottom of the recesses.

In the accompanying drawing, Fig. 1 shows a side View of a strip of metal from which the blanks are to be made by the practice of this invention.

Fig. 2 shows face and edge views of two rhombic pieces cut from the strip, the first step of the method.

Fig. 3 shows a section of the die and the end of the punch by which the pieces are cut from the strip.

Fig. 4 shows a face view of the die and section of the cutting punch acting on the strip.

Fig. 5 shows a side view of the rhombic piece in the shaping mechanism and before being compressed.

Fig. 6 is a top view of the elements illustrated in Fig. 5.

Fig. '7 shows the shaping mechanism closed and the rhombic piece compressed to substantially hexagonal outline, the second step of the method.

Fig. 8 is a section of the elements illustrated in Fig. 7.

Fig. 9 shows a face and an edge view of the compressed and expanded piece.

Fig. 10 shows the piece of Fig. 9 in a solid die and about to be recessed.

Fig. 11 shows the piece recessed, the third step of the method.

Fig. 12 shows the piece about to be pierced.

Fig. 13 shows the piece pierced, the fourth step of the method.

In following this method a strip of metal 1 is fed between a die 2 that has a rhombic opening, and a punch 3 which has a rhombic cutting edge, and a piece is severed. It is preferred to so feed the strip that the punch and die act to out every second piece from the strip and thus at one stroke of the punch two pieces are produced, that is the piece between the dotted lines on Fig.

1 is cut out so as to form two similar pieces 4 and 5, the former being punched through the die to the back and the latter dropping in front of the die.

The pieces thus produced are fed successively to a shaping mechanism which is comprised of complementary sections 6 and 7 that have their opposing walls shaped to substantially conform to four sides of the hexagonal blank to be produced. These sections may be fixed or they may be movable, and depthwise the opening between them is somewhat greater than the thickness of the stock used and the pieces that they are to receive. Cooperating with these sections of the shaping mechanism are two complementary sections 8 and 9 either or both of which may be movable. The latter sections are forced together by any suitable means, against the longer diagonal of the rhombic pieces in the sections 6 and '7. The opposing walls of these latter sections are shaped to produce the two remaining sides of the hex. The shaping sections 8 and 9 have ivings 10 and 11 that extend forward so as to embrace the sides of the metal being compressed. The width of the openings between these Wings is the same as the depth of the opening between the other shaping sections, that is, the openings are somewhat wider than the thickness of the pieces to be compressed. As a result of the pressure exerted on a piece in the direction of the longer diagonal, the metal, as it is compressed, expands outward transversely of the faces of the piece and cause it to fill the opening in the shaping sections and produce the piece 12 illustrated in Fig. 9.

The pieces which are now substantially hexangular and are of a thickness substantially the same as will be the thickness of the finished blank, are then fed to a die 13 which has a hexangular opening and which desirably has a conical upward projection 14 in its bottom. While in this die the piece is subjected to the action of a punch 15 that is hexangular in crosssection and has a boss 16 in its end, which produces a recess in the upper face and expands the metal outward therefrom against the Walls of the die so that the outer Walls of the piece will be in finished shape and condition.

Finally the pieces are fed to a die 17 that has an opening 18 and a punch 19 is forced through them to form the perforations. The scrap 20 that is removed by this punch, and which is. the only waste resulting from this method, is allowed to escape through the opening. After being pierced the finished blanks are ejected from thedie by a tubular plunger 21.

By reason of the production of the pieces in the form illustrated, two of which may be pro duced at one stroke of the cutting means, and the application of the compressing force on their longer diagonals so as to cause the metal to expand sidewise, the distance of flow of the metal is reduced to a minimum, consequently lesspoweris required to obtain perfect outlines, and when the metal is flowed the shortest distance, it does not become over-hardened. Furthermore it has been found that if the pieces are formed and pierced transversely of the length of the strip from which they are cut, as in this method, the perforations may be made easily and with less liability of tear and fracture of the walls of the opening produced by the piercing punch.

The invention claimed is:

l. The method of making hexagonal nut blanks which comprises cutting rhombic pieces from a cold strip of metal, and subjecting saidpieces topressure exerted on their longer diagonals and thereby producing substantially hexagonal pieces.

2. The method of making hexagonal nut blanks which comprises cutting rhombic pieces from a cold strip of metal, subjecting said pieces to pressureexerted on their longer diagonals and thereby producing substantially hexagonal pieces that are thicker than the original piece, and pressing central recesses in the thickened pieces and expanding them edgewise to complete hexagonal outline.

3. The method of making hexagonal nut blanks which comprises cutting rhombic pieces from a cold strip of metal, subjecting said pieces to pressure exerted on their longer diagonals and thereby producing substantially hexagonal pieces that are thicker than the original piece, pressing central recesses in the thickened pieces and expanding them edgewise to complete hexagonal outline, and piercing the pieces through the recesses.

l. The method of making hexagonal nut blanks which comprises cutting from a cold strip of metal, rhombic' pieces having obtuse angles of diagonals and thereby compressing them to thicker pieces of substantially hexagonal outline, and subsequently piercing said pieces;

'7.- The method of makinghexagona-l nutblanks which includes subjectingrhombicpiecesof coldmetal to pressure exerted on their longer diagonals and thereby compressing them tothicker pieces of substantially hexagonal outline, and subsequently recessing and then piercing said pieces.

JOSEPH W. GIBNEY. 

